Determining qualitative and quantitative characteristics of the blood of four
indviduals
Tracey Zhang
4A
Blood Lab
Purpose
The genotype of a person’s blood determines many characteristics that affect a
person’s life. This includes the blood type (A, B, or O) and whether it is marked with
the Rh factor (the presence of the chemical means the blood is positive, the absence
means it is negative). A blood type’s significance is that it indicates what types of
blood cannot be transfused into the person’s blood (blood type A cannot mix with
blood type B) because when an incompatible blood type enters a person’s body, the
person’s blood has antibodies that attack the “invading” blood. The presence of A, B,
or O chemical markers indicate the antigen and the presence/lack of Rh chemical
marker indicates whether the blood is positive or negative.
Therefore, the purpose of part A of the lab is to determine the blood types of four
people, Mr. Smith, Mr. Jones, Mr. Green, and Ms Brown. In part B of the lab, the
purpose is to find the number of red and white blood cells per cubic millimeter of an
unknown sample of blood.
Materials
To complete the lab’s purpose, two experiments (one for part A and one for part B)
will be set up. The experiment for part A first involves taking a sample of each of the
four people’s blood (simulated) and mixing it with anti-A serum, anti-B serum, and
anti-Rh serum. The second part of the experiment (part B) involves taking an
unknown sample of simulated blood and using a microscope to find the number of
red/white blood cells per square millimeter. This requires materials to complete.
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Blood typing slides (4x)
Toothpicks (12x)
Microscope Slide (1x)
Cover slip (1x)
Compound Microscope (magnification of 400x)
Marker
Unknown blood samples (4x; Mr. Smith, Mr. Jones, Mr. Green, Ms Brown)
Simulated Anti-A Serum
Simulated Anti-B Serum
Simulated Anti-Rh Serum
Procedure
Using the materials above, part A and part B of the experiment both need to be
successfully completed. The first part (part A) involves placing all four samples of
blood into the blood typing slides and placing anti-A serum, anti-B serum, and antiRh serum in one of the three wells on each slide. If a chemical reaction occurs, then
the blood is reacting to the serum, meaning that the A, B, or Rh chemical marker is
present. This method would determine the different blood types that the four
people have. Part B involves using a compound light microscope and counting the
red blood cells and the white blood cells in an unknown sample of blood and using
calculations to determine the number of red/white blood cells per cubic millimeter.
More detailed procedures are located below.
Part A:
1. Label each blood typing slide (Slide #1: Mr. Smith, Slide #2: Mr. Jones, Slide
#3: Mr. Green, Slide #4: Ms Brown)
2. Place three drops of Mr. Smith’s blood in each of the A, B, and Rh wells of
Slide #1.
3. Repeat step #2 with the three other blood samples (Mr. Jones, Mr. Green, and
Ms Brown) with each of the respective slides (Slide #2, Slide #3, and Slide
#4).
4. Place three drops of Anti-A Serum in each A well on the four slides.
5. Place three drops of Anti-B Serum in each B well on the four slides.
6. Place three drops of Anti-Rh Serum in each Rh well on the four slides.
7. Using three toothpicks per slide (12 toothpicks total), stir each well with a
separate, clean toothpick for thirty seconds.
8. Observe each slide and record any observations.
Part B:
1. Thoroughly shake one vial of WARD’s Simulated Blood.
2. Add one drop of simulated blood to a microscope slide and cover with a
cover slip.
3. Examine the slide on low power (100x) and find an area with an even
distribution of cells.
4. Switch to high power (400x), refocus, and count the number of simulated red
blood cells in the grid box. Record these results.
5. Count the number of simulated white blood cells in the grid box. Record
these results.
6. Repeat the counting procedure twice in steps 4 and 5 on two different grid
boxes. Record these results.
7. Calculate the average of the three red blood cell counts and the average of the
three white blood cell counts. Record these results.
8. Multiply the average of the three red blood cell counts by the dilution factor
and the average of the three white blood cell counts by the dilution factor to
find the number of red and white blood cells per cubic millimeter. Record
the results.
Conducting the Experiment:
The below pictures show the different steps and help better understand the process.
The first section illustrates part A of the experiment, which involves mixing samples
of blood and the anti-A/B/Rh serums. The first picture shows the samples of blood
before mixing with the serums and the second picture shows the blood after being
mixed. The next set of picture demonstrates part B of the lab. The first picture
shows my partner using a compound light microscope while the second picture
shows the slide used.
Part A:
Figure 1 shows the four simulated blood types in
blood-typing slides and labeled with each person's
name before being mixed with serums.
Figure 2 shows the results of mixing the simulated
blood types and the serums. A reaction means that
the chemical indicator is present (if the blood
reacts to anti-A serum, then the blood has the A
chemical marker on it).
Part B:
Figure 3 shows the compound light microscope
used to conduct the experiment. The microscope
contains levels of magnification from 10x to 400x.
For this experiment, 400x was primarily used,
Figure 4 shows the microscope slide used in the
experiment. It contains a grid, with the number of
red/white blood cells coming from one grid box.
Raw Data:
Part A:
Results of a mixture of four unknown types of blood and antiA/B/Rh serums
Anti-A Serum
Anti-B Serum
Anti-Rh Serum
Slide #1
(Smith)
Slide #2
(Jones)
Slide #3
(Green)
Slide #4
(Brown)
Reaction
No reaction
Reaction
No reaction
Reaction
No reaction
Reaction
No reaction
Reaction
No reaction
No reaction
No reaction
Figure 5 shows the results of the experiment conducted in part A, which determined each individual's
blood type.
Part B: Mr. Green’s blood
Number of cells in an unknown sample of blood
Blood Cell Type
Cell Count
1
Red
207
White
7
2
324
9
3
314
6
Figure 6 shows the number of red and white blood cells counted in three grid boxes from Mr. Green's
blood.
Processed data:
This data includes the conclusions drawn from the raw data collection that helps
complete the purpose of this lab. In part A, a reaction from any of the mixtures of
simulated blood and serum means that the chemical indicator is present in the
blood (ex. if the mixture of blood and anti-A serum begins to turn solid, then the
blood has the A chemical marker). Reactions (or lack of reactions) between the
simulated blood and anti-A/B serums determine whether the blood is type A, B, or
O. A reaction between the simulated blood and anti-Rh serum indicates whether the
blood is positive or negative. In part B, each of the red and white blood cell counts,
shown in Figure 6 is used to find the number of red/white blood cells per cubic
millimeter. This is done by taking the average of the red/white blood cells (281.67
and 7.33) and multiplying it by the dilution factor (150,000 and 5,000).
Part A:
Results of a mixture of four unknown types of blood and anti-A/B/Rh serums and
the blood type it indicates
Anti-A Serum
Anti-B Serum
Anti-Rh Serum Blood Type
Slide #1
Reaction
No reaction
Reaction
Type A
(Smith)
(Type A)
(Positive)
Positive
Slide #2
No reaction
Reaction
No reaction
Type B
(Jones)
(Type B)
Negative
Slide #3
Reaction
No reaction
Reaction
Type A
(Green)
(Type A)
(Positive)
Positive
Slide #4
No reaction
No reaction
No reaction
Type O
(Brown)
Negative
Figure 7 shows the type of blood each person has based on the data indicating the blood's reaction to
each of the serums.
Part B:
Number of cells per cubic millimeter in an unknown sample of blood based on
Figure 5
Blood Cell Count
Total
Average
Dilution Total Number of
Cell
Number
number of
Factor
blood cells per
1
2
3
Type
of Cells
cells or
mm^3 or average
Total of
number of cells x
Three
dilution factor
Red
207 324 314 845
281.67
150,000 42250500
White 7
9
6
22
7.33
5,000
36650
Figure 8 shows the total number of red and white blood cells in a cubic millimeter. This was found by
taking the average number of cells from three grid boxes and multiplying it by the dilution factor.
Calculation:
Average of red blood cells: (207 + 324 + 314)/3 = 281.67
Total number of red blood cells per mm^3 = average number of red blood cells x
dilution factor = 281.67 x 150,000 = 42250500
Discussion:
Part A:
From the results shown in Figure 5, it can be determined that Mr. Smith has type A
positive blood, Mr. Jones has type B negative, Mr. Green has type A positive, and Ms
Brown has type O negative. First, Mr. Smith’s blood was placed on a blood-typing
slide, with the anti-A serum and the anti-Rh serum causing the blood to begin
sticking together. This indicates the blood is reacting to the serum, meaning that the
chemical markers (A and Rh) are present in the blood. This occurs because when
the anti-A/Rh serum enters the bloodstream, the antibodies detect the invaders and
kill it. If the antigen (A, B, or O) is not present, then no reaction occurs because the
antibodies do not detect them.
The same setup was used for Mr. Jones’s blood. As shown in Figure 5, his blood
reacted to only the anti-B serum, meaning that he has Type B negative blood.
For Mr. Green, his blood reacted to the anti-A serum and anti-Rh serum. This
indicates that h e has type A positive blood.
Finally, Ms Brown’s blood reacted to none of the serums, meaning that she has type
O negative blood. Her blood type also shows that she is a universal donor, because
her blood type would not cause a reaction when transfused with any blood type.
Part B:
In part B of the experiment, the number of red blood cells and white blood cells
were counted in three grid boxes using a sample of Mr. Green’s blood. First, using a
compound light microscope, the number of red blood cells and white blood cells in
three grid boxes were counted. The averages of these three blood cell counts were
then calculated and the number per cubic millimeter was found by multiplying by
the dilution factor. Based on the number of red blood cells counted in the three grid
cells, the average is 281.67 and the number per square millimeter is 42250500.
Based on the number of white blood cells counted in the three grid cells, the average
is 7.33 and the number per square millimeter is 36650. From these numbers, it can
be seen that the number of white blood cells is much less than the number of red
blood cells (figure 8). Thus, the dilution factor for red blood cells is higher than the
dilution factor for white blood cells.
Conclusion:
Overall, the experiment determined the blood types of the four individuals and the
number of red and white blood cells in an unknown sample of blood; this also
determined the dilution factor. The experiment went well for the most part because
my group members and I followed instructions and did not have many problems.
However, the data in figures 6 and 8 are not completely accurate because of the
method used to gather it. To find the number of red and white blood cells, my
partner and I counted the number through the compound light microscope. It is
highly improbable that the numbers are exact but should be near the correct
number. If I could redo this lab, I would use a more accurate way of counting the
number of blood cells in a grid box and be more careful when mixing the blood and
serum so that it does not splash. If I could improve the experiment, I would
investigate the possible genotypes if offspring were created and determine if Rh
incompatibility issues exist.